Production of glass in strip form and apparatus therefor



Nov. 10, 1931.

E. B. LE MARE PRODUCTION OF GLASS IN STRIP FORM AND APPARATUS THEREFOR Filed April 27. 1929 Ym/AW/ A 2/0 A W W F A I o 00 0 9E 000000 0000 0 i 2 '11 /,lA VI 7 A v/ fizz/em Z 6836 741M feet per minute, which is suitablefor a lehr- Patented Nov. 1931 UNITED STATES PATENT caries BROTHERS LIMITED, OF

'ERIN'EST BRISTOW LE MARE,:QF ST. HELENS, ENGLAND, ASSIGNOR '10 PILKINGION LIVERPOOL, ENGLAND, .A'IBRITISH. REGISTERED COMPANY rzaontrc'rron or emss m STRIP roRmANn APPARATUS rumor.

' Application filed April 27, 1929, Seria1 No. 358,439, and in Great BritainMay 1, 1828.

This invention relates to the production of glass in strip form and has for its-object an improved apparatus whereby lengths of strip may be formed intermittently and the strips passed through a lehr at a speed equal t the speed of formation averaged over the periods of'formation and intermittence.

, In the production of glass in strip form, it is frequently necessary to form the strip at high speed, say, 30 feet per minute. If the strip were passed through a lehr at this speed, the necessary length oflehr would be iIIl-r practicable. I

It has been proposed to form strips at the desired high speed, but intermittently, the

, average speed of formation, including the time of intermittence,'being a speed, say, 3

of normal length, and certain devices have been proposed whereby the strip is received at the high speed andreduced in speed to the low speed.

According to this invention the strip is received at the high speed and reduced in speed 111 a way which is simpler, maintains'better.

the flatness of the strip and by simpler devices.

In the accompanying drawings z- Figural is a longitudinal section partly' broken away, of a lehr with roller bed according to one form of the invention,

Figure 2 is a side view of a portion thereof on a larger scale showing the driving devices of the rollers, and

Figure 3 is' 'art horizontal section through the line X- of Figure 2, showing the said driving devices.

Referring to the drawings, the 'lehr 1- is providedwith a bed of'rollers 2. The rollers 2 are driven by means to be hereinafter described at different speeds, being divided, for purposes of driving, into groups indicated by v the letters A, B, G and D in Fi ure 1. The

rollers of the group A, being t e rollers on which the strips of glass are-received as they are formed, either directly from the forming apparatus or after passage over a platen or other formof bed, are driven at a peripheral speed equal too'r slightly greater than the speed of formation of the strips. The rollers of the second group B are driven at a lower speed, those of the group C at a still lower speed and those of the group D at a still lower speed. The remaining rollers of the lehr,

ings 4 supported on a foundation wall5 out side the lehr wall 6. On the portions of the shafts 3 extending beyond the bearings 4 of certain of the rollers, are mounted free-wheel clutches having an inner member 7 and an outer member 8. The outer covering plate 9 of one of these clutches is not shown in Figure 2, so as to allow these members to be seen. The free-wheel clutches 7,8 may be of any type and need not be further described; their function is to enable the rollers to be driven at a given speed while leaving therollers free to turn at any higher speed.

The inner members 7 of the free-wheel clutches are fixed on the shafts 3 and chain wheels 10 are fixed on the outer members 8. The chain wheels 10 of the rollers. of any one roup of rollers are driven by a chain ers of two adjacent groups, the right-hand group, having a driving chain wheel similar to the wheel 12 of the left-hand group and the left hand group having idle wheels similar to the wheels 13 of the ri ht hand group.

For the purpose of descri ing the opera.- tion of the lehr, the following assumptions 'in regard to speeds, lengths and time will be made, namely, it will "be assumed that strips of glass 30 feet long are produced at a speed of 30 feet per minute, with intervals of nine minutes between. the completion of one strip and the start of the next strip; that the group A of rollers is 15 feet long and the rollers turned at the peripheral speed of 30 feet perminute; that the group B, C and D of rollers are respectively 29, 25 and feet long and the rollers driven through freewheel clutches at the speeds of 27, 22 and 14 feet per minute respectively; that the ordinary, rollers are driven at the speed of 3 feet r minute and are driven through freewheel clutches over a length of 30 feet.

The strip of glass 14 is received by the group A of rollers, which are driven at the speed of formation of the strip. When half the strip has passed on to the rollers of group A, its forward edge asses on to the rollers of the group B, whic are driven through freethese rollers becomes apprecia rest of the lehr.

wheel clutches and, therefore, offer no appreciable resistance tothe passage of the strip at a speed slightly higher than that at which they are driven. -When however, the back edge of the strip approaches the end of the group of rollers A, the strip is then being driven at 30 feet per minute by only a few rollers, while the greater portion of it is resting on the rollers of group B; then the resistance offered by the large number of le, and there is some slip between the strip and the rollers of grou A, which gradually increases as the num er of rollers of group A driving the strip diminishes. Thus the speed of the strip is gradually reduced from 30 feetper minute, namely the speed of the rollers of group A to 27 feet per minute, the speed of the rollers of group B.

Similarly, the strip passes from the rollers of group B on to those of group C, its speed is gradually reduced from 27 feet per minute to 22 feet per minute and, again, as it passes on to the rollers of group D its speed is gradually reduced to'14 feet per minute and, finally, as it passes on to the ordinary rollers, its speed is gradually reduced to 3 feet per minute, at which speed it passes through th In this way the speed of the strip from its formation to its passage on to the ordinary rollers is gradually reduced from 30 feet per minute to 3 feet per minute, without at any time exercising any retarding force likely to injure the strip and without allowing the strip to rest on a bed of rollers turning at too low a speed having regard to the temperature of the strip.

The next strip, formed after an interval of nine minutes, gradually approaches the strip previously formed, and reaches the latter when it has passed on to the ordinary rollers, so that,.on the ordinary r'ollers, which constitute the greater portion of the lehr,

the strips follow one another closely, and the lehr therefore is fully utilized.

The values of speed, length and time assumed above are taken only by way of example; the actual values are determined for for a period after its formation, the strip is at a'high temperature and soft, and conseguently the difference in speed between the rst and second groups of rollers must be small; as the strip becomes harder and harder, so the difference in speedbetween the following groups of rollers may be increased without causlng injury to the strip.

The interval between the formation of one strip and the next can be so related to the time taken by a strip to reach the ordinary rollers that the strips, when on the ordinary rollers, follow each other as closely as may be desired.

The means shown for driving the rollers by chains is by way of example only; they may be driven by any suitable devices, such as bevel or spiral gears.

that what I claim and desire to secure by Letters Patent is Roller-bed for intermittently receiving hot glass strips at a high s eed and reducin their speed, comprising a rst group of ro ers, a single driving means therefor adapted to drive the rollers continuously at aconstant speed corresponding to the speed of formation of the strip, a second group of-rollers, a single driving means therefor tending to drive the rollers thereof at a constant low speed and a free-wheel clutch between the latter driving means and each one of at least a portion of the rollers of thesecond group,- adaptedto permit each of the said rollers to turn freely at a higher speed than its driven speed. I

In witness whereof I have afiixed my signature hereto.

ERNEST BRISTOW LE MARE.

Having described my invention, I declare 

